Drill



J. D. CARR Dec. 26, 1933.

DRILL Original Filed March 26 1931 Patented Dec. 26, 1933 UNITED STATESPATENT OFFICE Application March 26, 1931, Serial No. 525,385 RenewedAugust 31, 1933 1 Claim.

This invention relates to a novel type of drill.

An object of the invention is to provide a drill of the characterdescribed having a substantially cylindrical head with a tapered lowerend, said head being provided with integral radial blades,

whose lower ends terminate in forwardly curved cutting edges beneath thelower end of the head,

said head also having a centrally located bit of the fish tail type atits lower end for cutting out the center of the bore to prevent theformation ot a core therein.

Another object of the invention is to provide a drill having acylindrical head, with radial side blades thereon, terminating inforwardly curved cutting edges beneath the head and having a centrallylocated bit at the lower end thereof with a large axial water channelextending downwardly through the head and branching into deliverychannels through which flushing fluid may be discharged on the forwardsides of said blades.

With the above and other objects in view, this invention has particularrelation to certain novel features of construction, "arrangement ofparts and use, an example of which is given in this specification andillustrated in the accompanying drawing, wherein:

Figure 1 shows a side-view of the drill partly in section, and v 4Figure 2 shows .a bottom end view thereof.

Referring more particularly to the drawing, the numeral 1 designates acylindrical head whose upper .end may be reduced and externally threadedproviding the shank 2 for connection to a drill collar by means of whichthe drill may be attached to a drill stem. The lower end 3 of the head1, is tapered downwardly and there is a centrally located bit 4preferably of the fish tail type at the extreme lower end of the head.

40 On the sides of the head are the radial blades 5 which extend outlaterally beyond the head and downwardly beneath the lower end of thehead.

The downwardly extended lower ends of the blades are widened inwardlyand are curved forwardly and terminate in the cutting edges as 6. Saidcutting edges may be provided with notches as 7 arranged in staggeredrelation to each other.

There is a relatively large axial water channel 8 leading downwardlythrough the head from the upper end thereof and this channel separatesinto the branches 9 which terminate on the downwardly tapering portion 3of the head in front of the respective blades and through this 35channel and its branches ample flushing fluid may be supplied to theforward sides of the blades to flush out the cuttings of the drill fromthe bore.

The drawing and description disclose what is now considered to be apreferred form of the invention by way of illustration only, while thebroad principle of the invention will be defined by the appended claim.

What I claim is:

A drill including an elongated head whose upper end is cylindrical andwhose lower end is tapered downwardly, the cylindrical portion of thehead having a relatively large axial water channel leading downwardlytherethrough from so the upper end of the head to said tapered portionand which separates into reduced downwardly diverging channels whichterminate on the downwardly tapering portion of the head, a centrallylocated bit formed integrally with the 88 lower endof the head, radialblades on the sides of the head and formed integrally therewith whoseupper ends are tapered upwardly and whose outer margins areapproximately parallel with the axis of the 'head, said blades beingexto tended downwardly beneath the head and being widened inwardly toconform to the taper of the head and whose lower ends terminate ininwardly widened cutting edges,vat a common plane with the cutting edgesof the central bit, said channels terminating in front of and in closeproximity to the forward sides of said blades.

7 JOHN D. CARR.

